Open Paleo

Phuwiangosaurus

Martin et al., 1994 POO-WYAHNG-o-SAWR-us

Named after the Phu Wiang area of Thailand where the fossil was discovered, combined with Greek sauros (lizard); meaning "Phu Wiang lizard".

137.1–125.8 million years ago Valanginian–Hauterivian, Early Cretaceous
Early Cretaceous stages

Phuwiangosaurus is a genus of titanosauriform dinosaur from the Early Cretaceous (Valanginian-Hauterivian) Sao Khua Formation of Thailand. The type species, P. sirindhornae, was described by Martin, Buffetaut, and Suteethorn in a 1993 press release and was formally named in 1994. The species was named to honor Princess Maha Chakri Sirindhorn of Thailand, who was interested in the geology and paleontology of Thailand, while the genus was named after the Phu Wiang area, where the fossil was discovered. The precise affinities of Phuwiangosaurus among titanosauriform sauropods are uncertain, though several studies have classified it as a euhelopodid.

Diagnosis

  1. Medium-sized sauropod 15-20 m long
  2. Anterior cervical vertebrae with very low and wide neural arch, showing dorsoventral flattening rather than transverse compression
  3. Posterior cervical vertebrae with high, widely bifurcated neural spine without median spine
  4. Large zygapophyses situated low and far from each other, strongly diverging laterally from centrum
  5. Posterior dorsal vertebrae opisthocoelous with deep pleurocoel and well-developed laminae/cavities system
  6. Posterior dorsal vertebrae with unbifurcated, elongated neural spine, long diapophyses directed more dorsally than laterally
  7. Hyposphene-hypantrum system present
  8. Femur flattened anteroposteriorly with fourth trochanter crest-shaped, located medially above midlength of shaft
  9. Very developed lateral epicondyle at distal end of femur

Species

Phuwiangosaurus sirindhornae Martin et al., 1994

Type species

Named for Princess Maha Chakri Sirindhorn of Thailand, who was known for an interest in the geology and paleontology of the country.

Holotype
SM PW1-0001, SM PW1-0002, SM PW1-0003, SM PW1-0004, SM PW1-0005, SM PW1-0006, SM PW1-0007, SM PW1-0008, SM PW1-0009, SM PW1-0010, SM PW1-0011, SM PW1-0012, SM PW1-0013, SM PW1-0014, SM PW1-0015, SM PW1-0016, SM PW1-0017, SM PW1-0018, SM PW1-0019, SM PW1-0020, SM PW1-0021, SM PW1-0022 , Sirindhorn Museum
Material
Partial skeleton: three cervical vertebrae, four dorsal vertebrae, several ribs, left scapula and distal end of right scapula, left humerus and part of left ulna, both sides of pelvis, both femora, left fibula.
Horizon
Sao Khua Formation, Valanginian–Hauterivian, Early Cretaceous , 137.1–125.8 million years ago
Locality
Phu Pratu Teema (Phu Wiang site I), Khon Kaen, Thailand

Notable specimens

  • SM K11

    Sirindhorn Museum most complete

    The most complete known skeleton of Phuwiangosaurus, about 60% complete and representing a half-grown individual. It includes a partial skull, anatomy not preserved in the holotype.

    Suteethorn et al. (2009)

References

  1. Suteethorn, S.; Le Loeuff, J.; Buffetaut, E.; Suteethorn, V.; Talubmook, C.; Chonglakmani, C. (2009). A new skeleton of Phuwiangosaurus sirindhornae (Dinosauria, Sauropoda) from NE Thailand. Geological Society, London, Special Publications 315(1): 189-215. doi:10.1144/SP315.14 suteethorn2009a
  2. Martin, V.; Buffetaut, E.; Suteethorn, V. (1994). A new genus of sauropod dinosaur from the Sao Khua Formation (Late Jurassic or Early Cretaceous) of northeastern Thailand. Compte Rendus de l'Academie des Sciences, Paris, série IIa 319: 1085-1092. martin1994a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b